(i) Technical Field
The present invention relates to a semiconductor device, and more particularly, to a semiconductor device having a GaN-based semiconductor layer doped with Fe.
(ii) Related Art
In a semiconductor device with a GaN-based semiconductor containing GaN, there is known a technique for doping GaN with Fe to realize high resistance of the GaN-based semiconductor layer. It is expected that doping of GaN with Fe improves the characteristics of devices such as FET (Field Effect Transistor) and HEMT (High Electron Mobility Transistor). For example, leakage current may be suppressed and the pinch-off characteristic may be improved. Doping of GaN with Fe is described in, for example, S. Heikman et al., “Growth and characteristics of Fe-doped GaN”, Journal of Crystal Growth 248 (2003) 513-517, or W. Lee et al., “Optimization of Fe doping at the regrowth interface of GaN for applications to III-nitride-based heterostructure field-effect transistors”, Applied Physics Letters 90, 093509 (2007).